PPC is an Internet marketing formula used to price online advertisements. In PPC programs the online advertisers will pay Internet Publishers the agreed upon PPC rate when an ad is clicked on, regardless if a sale is made or not. Pay per click in search engine advertising, the advertiser would typically bid on a keyword so the PPC rate changes.
Adword is actually a program to be considered when weighing your pay per click choices . it is slightly different than a real pay per click program in that page advertised listing are ranked based on a daily spending budget and received click through not simply merely on bid amount
Pay per Click...as name suggests you have to pay for a click on your listing visible on search engine..